The present invention relates to musical instruments and more particularly to a novel banjo construction. Specifically, the invention is directed to (1) construction of a pot sub-assembly comprising a tone ring/rim structure (2) a method of and (3) an apparatus for securing the metal tone ring of a banjo to the wooden rim under a tight, uniform and permanent radial compression.
A search of the prior art failed to uncover any prior art references which disclose the novel aspects of the present invention. Several patents were uncovered which disclose a variety of banjo constructions. The following is a listing of the patents uncovered during the aforesaid search: U.S. Pat. No. 1,701,420; U.S. Pat. No. 3,240,096; U.S. Pat. No. 3,921,492; U.S. Pat. No. 4,226,159.
The pot assembly of a conventional construction comprises a circular non-metallic (usually wooden) rim to which is fitted a metal tone ring and a plastic or animal-skin "head" stretched over the tone ring by an annular hoop tensioned by means of a plurality of hooks mounted to a resonator flange. Heretofore in the art of banjo design and construction there have been numerous types and configurations of tone rings fitted to the wooden rim of the banjo pot assembly, the various tone ring configurations being intended to enhance the sound of the banjo instrument.
In the art of banjo construction, the tone ring and wooden rim are machined to particularly precise diametrical tolerances so as to obtain a substantially zero clearance between the inside diameter of the ring and the outside diameter of the rim. The tone ring and wooden rim are then hand mated by carefully pushing and/or rotating one to the other to obtain as snug a fit as possible.
Quality and volume of the sound of the banjo is directly related to the snugness of the fit among the various components of the banjo pot assembly, and especially to the uniformity and tightness of the fit between the tone ring and the wooden rim. Consequently, there is a limitation on the quality and volume of sound that may be obtained. Furthermore, shrinkage of the wood with time can also cause a significant loss of sound quality and volume, such as, for instance, damping and distortion of vibration, even though at the time of manufacture the banjo sound quality and volume characteristics were entirely acceptable.
One way of overcoming the problem of looseness between the tone ring and wooden rim is a relatively recent innovation known as the Stelling pot to which the above-listed U.S. Pat. No. 3,921,492 is directed. According to the Stelling pot construction, the tone ring is provided with a beveled surface which is wedgingly related to a wooden rim whereby tightening of the head insures a snug and intimate contact between the tone ring and rim. In the Stelling design, however, the structure of the wooden rim has a beveled surface which precludes the use of popular, existing cylindrical-walled structures. Such cylindrical-walled types are known for excellence of sound provided a tight tone ring/rim structure can be achieved and maintained.